# Data Structure Information

## Overview of the OS NGD data structure

OS NGD data is different from our other products because you access it from a single source where you'll find the data you need without having to download unnecessary datasets. It also has a simple data structure, designed to help you quickly answer questions and develop more intelligent solutions.

<figure><img src="/files/CPKYHnSiqtJl4mkDGp53" alt="Infographic showing OS NGD terminology and data structure: themes, collections, feature types and features."><figcaption><p>OS NGD data structure: themes, collections, feature types and features.</p></figcaption></figure>

OS NGD data has been categorised to make it easier and quicker for you to discover the data you need:

* **Themes**: Geographic data of Great Britain is structured into nine themes of related items.
* **Collections**: Each theme is made up of one or more collections, which in turn have feature types.
* **Feature types**: Feature types are the most granular level, with objects (features) grouped by geometry or classification.

<figure><img src="/files/jyhHAHBXqXkJ2AocxT7S" alt="Image showing a simple map of Great Britain. The 9 OS NGD data themes names are listed: Address, Administrative and Statistical Units, Buildings, Geographical Names, Land, Land Use, Structures, Transport, and Water."><figcaption><p>The nine OS NGD data themes.</p></figcaption></figure>

{% hint style="info" %}
More in-depth information about OS NGD data terminology (themes, collections, feature types) is available from the [OS NGD Fundamentals pages](/osngd/getting-started/os-ngd-fundamentals.md) – these pages cover core elements of OS NGD design, including available data formats and file naming, data schema versioning, access methods, data ordering and currency, attribute information for feature types, unique identifiers and coordinate reference systems.

We recommend that you refer to the OS NGD Fundamentals pages as you work your way through this Data Structure section.
{% endhint %}

## Explore OS NGD data

Content in this section is ordered by themes, collections and feature types, mirroring the OS NGD data structure itself. This level of categorisation should make it easier and quicker for you to discover the data you need.

For example, if you are interested in water or river data, then you should select 'OS NGD Water' from the card below or the left-hand-side navigation menu, then drill down through the collections to the water feature type/s that interest you.

**OS NGD themes**

<table data-view="cards"><thead><tr><th></th><th data-hidden data-card-target data-type="content-ref"></th><th data-hidden data-card-cover data-type="image">Cover image</th></tr></thead><tbody><tr><td><strong>OS NGD Address</strong></td><td><a href="/pages/wQji23Gqyfn4n09uLK3F">/pages/wQji23Gqyfn4n09uLK3F</a></td><td data-object-fit="cover" data-alt="Example image showing OS NGD Address data. A background map is included for context."><a href="/files/U8aHHu52iE46PYEdsofP">/files/U8aHHu52iE46PYEdsofP</a></td></tr><tr><td><strong>OS NGD Administrative and Statistical Units</strong></td><td><a href="https://docs.os.uk/osngd/data-structure/administrative-and-statistical-units">https://docs.os.uk/osngd/data-structure/administrative-and-statistical-units</a></td><td data-object-fit="cover" data-alt="Example image showing data from the OS NGD Administrative and Statistical Units Theme. A background map is included for context."><a href="/files/bxL4bG97zeR5Qx5CTgQg">/files/bxL4bG97zeR5Qx5CTgQg</a></td></tr><tr><td><strong>OS NGD Buildings</strong></td><td><a href="https://docs.os.uk/osngd/data-structure/buildings">https://docs.os.uk/osngd/data-structure/buildings</a></td><td data-object-fit="cover" data-alt="Example image showing data from the OS NGD Buildings Theme. A background map is included for context."><a href="/files/aCDVmVhH9POfLysrvJXY">/files/aCDVmVhH9POfLysrvJXY</a></td></tr><tr><td><strong>OS NGD Geographical Names</strong></td><td><a href="https://docs.os.uk/osngd/data-structure/geographical-names">https://docs.os.uk/osngd/data-structure/geographical-names</a></td><td data-object-fit="cover" data-alt="Example image showing data from the OS NGD Geographical Names Theme. A background map is included for context."><a href="/files/DWPDOKrumRKmNf5keLgJ">/files/DWPDOKrumRKmNf5keLgJ</a></td></tr><tr><td><strong>OS NGD Land</strong></td><td><a href="https://docs.os.uk/osngd/data-structure/land">https://docs.os.uk/osngd/data-structure/land</a></td><td data-object-fit="cover" data-alt="Example image showing data from the OS NGD Land Theme. A background map is included for context."><a href="/files/Esu1F1h6TAgcMiCufnvl">/files/Esu1F1h6TAgcMiCufnvl</a></td></tr><tr><td><strong>OS NGD Land Use</strong></td><td><a href="https://docs.os.uk/osngd/data-structure/land-use">https://docs.os.uk/osngd/data-structure/land-use</a></td><td data-object-fit="cover" data-alt="Example image showing data from the OS NGD Land Use Theme. A background map is included for context."><a href="/files/h4948S7Q14jpU3esWU8v">/files/h4948S7Q14jpU3esWU8v</a></td></tr><tr><td><strong>OS NGD Structures</strong></td><td><a href="https://docs.os.uk/osngd/data-structure/structures">https://docs.os.uk/osngd/data-structure/structures</a></td><td data-object-fit="cover" data-alt="Example image showing data from the OS NGD Structures Theme. A background map is included for context."><a href="/files/P3X5RfMJ1Nay6vM2PBPC">/files/P3X5RfMJ1Nay6vM2PBPC</a></td></tr><tr><td><strong>OS NGD Transport</strong></td><td><a href="https://docs.os.uk/osngd/data-structure/transport">https://docs.os.uk/osngd/data-structure/transport</a></td><td data-object-fit="cover" data-alt="Example image showing data from the OS NGD Transport Theme. A background map is included for context."><a href="/files/sdGLZIGUZ8zpEFgb7QbO">/files/sdGLZIGUZ8zpEFgb7QbO</a></td></tr><tr><td><strong>OS NGD Water</strong></td><td><a href="https://docs.os.uk/osngd/data-structure/water">https://docs.os.uk/osngd/data-structure/water</a></td><td data-object-fit="cover" data-alt="Example image showing data from the OS NGD Water Theme. A background map is included for context."><a href="/files/NQs0c8evVJS4FddcvXwT">/files/NQs0c8evVJS4FddcvXwT</a></td></tr></tbody></table>

***

## What's next?

<table data-view="cards"><thead><tr><th></th><th></th><th data-hidden data-card-target data-type="content-ref"></th></tr></thead><tbody><tr><td><h3><span data-gb-custom-inline data-tag="emoji" data-code="1f4dd">📝</span> Code Lists</h3></td><td>Access all of the code lists for the OS NGD.</td><td><a href="/pages/mL8yUolgtiKSYaCbqO88">/pages/mL8yUolgtiKSYaCbqO88</a></td></tr><tr><td><h3><span data-gb-custom-inline data-tag="emoji" data-code="1f4d6">📖</span> OS NGD Fundamentals</h3></td><td>OS NGD Fundamentals covers the core elements of OS NGD design, including available data formats and file naming, data schema versioning, access methods, data ordering and currency, attribute information for feature types, unique identifiers and coordinate reference systems.</td><td><a href="/pages/ZwTU61QrkbSYYHKCvgV4">/pages/ZwTU61QrkbSYYHKCvgV4</a></td></tr><tr><td><h3><span data-gb-custom-inline data-tag="emoji" data-code="25b6">▶️</span> Getting Started</h3></td><td>Our getting started guides will help you access, use and style OS NGD data. <br><br>You'll also find FAQs, in-depth information on OS NGD design, and webinars, tutorials and case studies.</td><td><a href="/pages/xrEvsNtByZnphIFRsKDj">/pages/xrEvsNtByZnphIFRsKDj</a></td></tr><tr><td><h3><span data-gb-custom-inline data-tag="emoji" data-code="1f4e3">📣</span> OS NGD News</h3></td><td>Learn about new data enhancements and service updates released for the OS NGD, the change log, improvements, planned future data enhancements and recent announcements.</td><td><a href="/pages/uzC8wDtt7f2Ty8UJ6nQa">/pages/uzC8wDtt7f2Ty8UJ6nQa</a></td></tr><tr><td><h3><span data-gb-custom-inline data-tag="emoji" data-code="2699">⚙️</span> Data and Service Status</h3></td><td>Find out about OS NGD planned maintenance, any live service disruption, current data issues and resolved data issues.</td><td><a href="/pages/nuzHLScuJ8F6WWfXkgH0">/pages/nuzHLScuJ8F6WWfXkgH0</a></td></tr><tr><td><h3><span data-gb-custom-inline data-tag="emoji" data-code="1f5fa">🗺️</span> OS NGD Sample Data</h3></td><td>Download OS NGD sample data or visualise it online.</td><td><a href="/pages/R3XBYZMhWtAlUYl6CddH">/pages/R3XBYZMhWtAlUYl6CddH</a></td></tr></tbody></table>


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